Does plating a cylinder change the castings properties?

[MikeS]

Curious as my black cloud follows me.

First I am not complaining here as I have no issues with the plater or Eric's services..

I have a big bore RM85 that Eric has done. History goes like this:

1. Sept 2002 O3 Cylinder made/plated at factory.
2. Oct   2002 Eric bores and replates it.
   May  2003 Bike Overheats BAD. Eric hones cylinder (says it is warped but it may last for a race or 2)  (N/C... THANKS ERIC)
3. June 2003 Eric sends it out for replate. The process is flawed and cylinder needs to be bored some more to clean up warping. It is replated Again.
4. Thicker coating is applied. (N/C for rebore and replate as the warpage got overlooked. Only got charged for a normal replate)
Sept 2003 Plating falls off after approx 6 hours of race time.
5. Oct   2003 Replated again (2 days ago) ( N/C Thanks Eric and US Chrome)

Well Yesterday I recieved the cylinder as promised (THANKS AGAIN ERIC). Last night I assembled everything. I torque the head bolts in 3 stages with a Good Torque wrench. The 2 rear head bolts pulled the threads out of the cylinder. Well I put 2 heli coils in. I assembled it again and the front 2 pulled out. OK ... I installed 2 more heli coils. I have not assembled it again as it got late and I was POed. I plan on getting some new bolts/studs this morning just incase. Junior has a race Saturday (tomorrow) morning.

My Question here is can all that plating (5 times) cause the threads to become brittle ?

Mike

 


 

 

[endosports]

after 5 trys why didn't you have the cylinder sleeved?

 

[Rich Rohrich]

Mike - I'm not sure if the plating strip bath has long term effects or not. I'll be talking to Eric later and see what his thoughts are.

 

[jmics19067]

I am more inclined to think the threads gave out in the aluminum from the constant working in and out of the studs. Interesting stuff though.

 

[MikeS]

Rich
I tried to call Eric but his number kept going to the Phantom voice mail box.

Endo
Sleeving is not possible in this senario.

JM

I had the studs in and out about 8 times I figure. So I assume that is possible also.

Well .... The head is smoke at this point because 2 of the 4 helicoils let go. I salvaged one by using an extra long coil. Problem is the aluminum is crumbleing. Even tapping it with oil made for the aluminum will not allow a clean cut for the helicoils. It was too late last night and I overlooked that.

I put some loctite crap that has hardened on the one and it took the torque. Even after a hot cold cycle of breaking the topend in it has held. It needs to hold for an hour or so for tomorrows race. I have 3 weeks before the next race so I will try one more patch on the bad coil.
I am patching only to make 2 more hours of racing. I ordered a new cylinder but I want Eric to try a stroker and long rod kit and I do not want to cut the new cylinder base way down to match the current configuration.

Something new to add to the racing diary...

 

[jmics19067]

I salvaged one by using an extra long coil. Problem is the aluminum is crumbleing. Even tapping it with oil made for the aluminum will not allow a clean cut for the helicoils.

hmmm well the aluminum threads pulling out from repeated use wouldn't explain that.

 

[SamLS]

I have had the same thing happen to me after I welded the transfers on some cylinders. I let them get too Hot. Some of the studs wouldn't come out without stripping. I drilled oversize and used a thread forming tap ( no flutes ) with a good moly lubricant I believe it was made by Castrol for tapping. I used a die and made some plugs out of 6061 AL installed with JB weld and tapped them for new studs. You did say the engine overheated. How hot is the plating bath? Any ideas alloy and composition is used in cylinders?

 

[MikeS]

I think JB weld will be my next choice.

We made 45 minutes out of the 65 for the race. The bike ran to the finish and we lost only one place. The stud was lose and the coolant was gone.

This cylinder was warped around .015 out of round. It was run real hot a few times as it had the previous season as an 85. I have 6 piston from the collection that are siezed from our overheating problem. Overheating was solved a few months ago after the 2nd last replate.

 

[jury vjr]

I am not for sure, but every time youre cylinder needs to be replated,the old nicasil has to be removed with salpetresour.And a while ago,I talked with pierre karsmakers from the netherlands(He has a very famous replating shop now)and he said that every time a cylinder is in a salpetresour bath to remove the old nicasil,the cylinder becomes more porous.Maybe thats the reason that the threads became weaker.

 

[cujet]

Mike, it sounds like the aluminum got too hot at some point in it's life. The situation you describe is typical of overheated aluminum. This sort of thing happens around the exhaust ports on aluminum automobile heads that have been run without water.

I hope you figure the problem out.

Chris

 

[MikeS]

I finally got to speak to Eric on this after 2 weeks of phone tag.

Yes it got real hot more than once.

Eric mentioned that the Suzuki cylinders have a hi silicon content. That makes them "gummy" even thread inserts are a pain to get to hold. I have given it one more shot at mending. I had some specialty studs made that are longer and they seem to go deeper into the extra long thread coils I got. I also used JB weld to secure everything in place.

If they hold great we need one more 2 hour race than I could care less.

thanks for all the comments and reading about my mess.

 

[jmics19067]

I can understand the high silcon content giving you troubles, Although I am by no means an expert maybe a different style of tap and tapping process is in order.Instead of a standard 4 fluted straight shank tap in the tighten half back off 1/4 style of tapping maybe something like a three spiral fluted tap in a constant feed would be better suited to that material. or some type of strange combination of type of tap ,process and or cutting fluid is needed for a clean cut.

unfortunately that will basicly leave out helicoils since I only know of type of helicoil tap <4 straight flutes>. Possibley you might be able salvage things for the long run if you could get a standard oversized tap in the right configuration for the casting and make the holes big with a clean cut thread. Then get some 6061 rod or something more tapping friendly,wind the screw in on the side of your die to cut a slightly oversized outside thread on the rod to have a slight intereference fit in the holes of the jug and loctite them in. Center drill the rod for your stainless helicoils and then loctite them in,let set clean up any loctite that could grab onto your studs and install studs.
I could see most of this work being done on a common drill press but you will most likely have to have the top of the cylinder surfaced so there in no ridges from the installed homemade nutsert rods.Whether or not water jacket holes or head gasket sealing of the fine cracks from the rod to cylinder thread is going to be a problem but if you are going to be ending up throwing the jug away I would try it as a last resort.

IF my idea pans out the way I envision it you could possibley have a very course thread holding your "nutserts" so crumbling isn't as much of a problem for thread contact at the jug and then a material more able to handle the work of removing and reinstalling the studs often.

did that come out clear? Hopefully a machinist could tell you if it is a sound idea to try.

 

[bigred455]

Try millenium technoligies next time!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[Neil Wig]

The old air cooled VWs had similar problems with their magnesium cases. They would pull head studs very easily. The solution is to use "case savers". Basically, these are steel threaded inserts (not helicoils). You machine the cylinder to accept the threaded insert, screw the insert in with a high strength loctite, and machine the insert flush to the cylinder. From there, you have an extremely strong mounting point for your head stud.

A little time consuming, but should provide a good permanent fix.

Later

Neil.

 

[MikeS]

Originally posted by bigred455
Try millenium technoligies next time!!!!!!!!!!!!!!!!!!!!!!!!!!!

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It would not have made a difference who did the work.

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I think inserts are better than coils. I have some over size inserts coming that will cut threads as they are inserted. If they donot look correct then I will get some stock and make my own.

 

[DEANSFASTWAY]

Mike S try out Mc Master Carr catalog or MSC catalog for thread inserts. Its not the place where you had the job done thats at fault so Its not likeMillenium is a saving grace Its not Erics fault either.. This happens every time you get something coated . Every timne I cet a cyl recoated I have to clean out the threads with a bottoming tap and now I do it as a rule. Trouble is (and not a big one) There is not much room left on your RM cyl and if you put alot of inserts etc it may distort the cyl bore walls when installed . Youll want to install all of the coils and studs and them have the cyl rigid honed not ball honed to make sure the bore is totally round. This is a real good idea and might help disway a future seizure.ON 400Exs and XR 400s they also pull out the cyl studs and blow gaskets. When you bore a 400 Ex out the sleeve gets real thin and after a seasons use when refreshening you can actually see a pattern near the suds on the cyl bore where the rings wore deeper . For this reason and this motor I built a torque plate so I torque against the studs to make it seem like the cylinder head is installed , then finish hone. On your 80s and 125s Ill use the original studs and use 4 old wrist pins with washers at the cyl top and torque the head stud nut down then finish hone if I think there is a problem.Sometimes theres only so much time you can throw at something until youve got to scrap or save for a momento. The aluminum seems to get kinda brittle esp Japanese , Its funny but on like ktms and huskys and stuff it always seems to be a higher quality of cast and denser aluminum. GLMF

 

[DEANSFASTWAY]

Mike S Did you ever see some of the Honda cylinder studs . one end is 10mms at cylinder and 8mm shaft . you might want to check that out also.

 

[MikeS]

Originally posted by DEANSFASTWAY
Mike S Did you ever see some of the Honda cylinder studs . one end is 10mms at cylinder and 8mm shaft . you might want to check that out also.

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Thanks

I thought about chucking a 10 mm bolt in the lathe and making that style stud. But the material is thin already. The holes are opened up pretty good already since the helicoils are in place. I just got some inserts from TIME SERT that are 8mm and oversize body for fixing bad helicoils. They will probably just touch the outer oring or make that area as thin as paper :( .&nbsp;

I already have the new cylinder but need it modified by Eric. That will be done later.&nbsp; I need about 1 hr / 15 minutes time out of this one and it can go on the shelf :yeehaw: &nbsp;

 

[jmics19067]

You wanna drive the tech guys crazy? how about if you assemble the engine and then make some type of strap to help hold the head down tight. Kinda like blower straps on a dragster.

 

[DEANSFASTWAY]

Itll probably still leak water.

 

[jmics19067]

I am not going to say it is feasible due to space/manufacturing difficulties but I am not so sure that the head gasket would care if it is getting squeezed by the studs and nuts as we know it or being compressed by an external force.

If you could assemble the engine and then make a plate that would set evenly on the head nuts and for instance make a plate that would bolt on to the cylinder studs using threaded rod to join the two plates together I am certain you would be transferring some of the stress off of the crumbling cylinder to head threads down to the cylinder to crankcase threads. This would be a quick for instance with a couple of problems, overstressing the cylinder to crankcase threads a real possibility. Whether you could make a bracket from say the cylinder head stay to a radiator mount and push down might be an answer for that.

there are quite a few problems with, figuring out and actually trying to manufacture this thing, getting accused of cheating and having to tear down at a tech inspection to prove it is not illegal, and getting laughed at for even listening to this cockamamy idea :eek: . But the only thing you really have to do is clamp the head down even and tight enough for the gasket to seal

 

[DEANSFASTWAY]

Can yousay McGuyver? Home Cheapo makes those turnbuckles for like screen doors and stuff . theyve got smaller ones with 5/16 thread and 2 eyelets .Once we had a 2 sroke sled that we put a small blower on and it kept pushing the pipe springs off and the pipe csame unhitched. We used them and they worked real well. Then our boost controller froze up and the motor pushed out the crank seals when boost came up. That thing needed seat belts. Jimics hows the It 465/YZF 426 project going?

 

[jmics19067]

Project 1/2 Wr-IT < the r is silent :confused: > is at a momentay standstill

still stuck at the pipe and tank. since those projects are going to take some time I am back shelving it till I get some other things done<family,home and money making stuff>. Since making a fuel tank and pipe is going to be stretching the limits of my knowledge,shop working skills, and patience to the breaking point. I will need a clear conscience and garage before I try and tackle those things.

Unfortunately I have had made a living backyard engineering a lot of goofy stuff for quite some time. seriously tainted my mechanical aptitude and thought processes but anything to avoid having to call a wrecker if I could get the truck back to the shop.

Mcguyver was my hero for a while replaced by Junkyard Wars and Monster Garage :)

 

[EricGorr]

Hi Mike, the cylinder replating process can change the material properties of some cylinders but only if they are welded and prepared by pre-heating, or if the cylinder is cleaned in a type of cleaning oven used in automotive machine shops intened for cast iron blocks. Your cylinder wasn't welded but the RM cylinders have a high percentage of silicon which tends to roll the peak of the thread over time. Unlike any of the aftermarket plating companies I install a stainless steel bolt in all the threaded holes to prevent the tri-acid pretreatment from erroding the peak of the thread and reducing the chance of glass-bead media from getting trapped in the threads, but Sh%t happens in plating. Gilardoni uses the same type of alloy as Suzuki for their Husqvarna cylinders and they install stainless wire inserts in the threads right after the manufacturing process.

Thread-Serts work pretty well, its a common problem on RM80/85s mainly because they only have 4 studs retaining the head.